Volume 1, Issue 2 (January 1979)

A Room Temperature Stable “B” Staging Epoxy Resin System

We have discovered a new curing agent for epoxy resins that has both interesting and useful properties. The compound, 2,5-dimethyl-2,5-hexane diamine (DMHDA) is a sterically hindered, primary aliphatic amine. As a curing agent for DGEBA epoxy resins, it has the following desirable characteristics: (1) at room temperature, it forms a stable “B” stage resin; (2) it is a good wet-filament-winding resin having both a low viscosity (0.5 Pa…s) and a long gel time (21 h for a 30-g mass); and (3) the cured resin properties are good, e.g., the tensile strength is 86 MPa (12,500 psi) and the glass transition temperature is greater than 140°C when cured at 130°C.